Micrometer attachment



y 1933- w. HECKERSDORF ET AL 1,910,467

MICROMETER ATTACHMENT Filed June 10, 1930 /5 ma 5 7 2/6/70 22 24 /0 i INVENTOR. WaZZ'e z Awfitsdol ATTORNEY.

Patented May 23, 1933 unrrso srarss WALTER HECKERSDORF AND HENRY POPIPENHAEGER, 015 DETROIT, MICHIGAN MIGROMETER ATTACHMENT Application filed June 10,

This invention relates to improvements in micrometer attachments. We are aware that attachments have been employed for gauges wherein balls were provided portions of which projected so as to be rotatable against stationary surfaces of work to be measured. 7

This invention, however, aims to provide micrometer attachments readily attachable to, or detachable from, micrometers so that the exact outside diameters or pieces of work may be determined while the latter are being rotated in a machine without fear of either attachment moving relative to, or becoming disengaged from, the portion of the micrometer on which it is mounted.

Another object of the invention is to provide micrometer attachments which are both simple and cheap to manufacture, and which may be readily mounted on or removed from a micrometer.

lVith these and other objects and advantages in view which will become apparent as the specification proceeds, the invention, which consists in certain novel construction and combination of parts, is hereinafter more fully described with the aid of the accompanying drawing, in which:

Figure 1 illustrates a conventional micrometer with the attachments thereon.

Figures 2, 3 and 4 are enlarged sections 011 the lines 2-2, 33 and 44; respectively of Figure 1.

Figures 5 and 6 are enlarged details.

Referring to the drawing, 1 designates a conventional micrometer consisting in part of a fixed anvil 2 projecting inwardly from one extremity 1a of the micrometer. Movable through the opposite extremity 1b of the micrometer and in alignment with the axis of the anvil 2 is a member 8. Between the opposed extremities of the said anvil 2 and member 3 work is measured.

The invention consists in the provision of attachments 5 and 6 and their construction 1930. Serial No. 460,268.

by which they-may be readily mounted so that portions of them project towards one another from the anvil 2 and member 3 respectively in such a manner that rotating work may be accurately measured between them. I

The attachment- 5 consists of a body 7 having an aperture 8 through it which is of such width as to receive the sides of the micrometer extremity la, and the length of this aperture is somewhat greater than the distance from the outer end of the anvil 2 to the outer side of the micrometer extremity 1a.

One end of the aperture8 is decreased in size to form a recess .9 to .receive the outer end of the anvil 2, and a screw 10 is in threaded engagement with a threaded opening 10a in the body 7 and extends into the opposite end of the said aperture. This screw 10, which may at its inner extremity be provided with a bearing plate 10?), is tightened against the outer side of the micrometer extremity 1a and holds-the body 7 firmly in place.

In the extremity of the body 7 remote from the screw 10 is a cavity 11 having a block 12 therein in the outer face of which a concavity 13is formed. In threaded engagement with the periphery of this extremity of the, body is an annular cap 14 by which a ball 15 is so held against the concavity 13 that it is free to rotate. The outer portion of the ball projects beyond the outer side of the cap 14; A substantially central knockout hole 16 extends through the body 7 from the base of the recess 9 to the cavity 11 through which an instrument may be inserted when it is desired to remove the block 12 which should be a tight fit in the said cavity. A depression 17 extends inwardly into the block 12 from the cavity 13 which forms an oil reservoir.

The attachment 6 consists of a sleeve 18 split longitudinally from one extremity for a portion of its length so that the sleeve is divided into a plurality of segments. The split end of the sleeve is bored out to fit around the outer portion of the member 3, and its outside diameter is preferably reduced to receive a clamp 19 by which the split sleeve is held securely on said member. The opposite extremity of the sleeve is also bored out to receive a block 20 which has a concavity 21 formed in its outer face. This extremity of the sleeve is externally threaded to receive an annular cap 22 by which a ball 23 is revolvably held against the concavity 21. Through the intermediate portionof the sleeve is an aperture 24 of reduced size through which an instrument may be inserted to remove the block 20, and 25 denotes an oil reservoir formed in the latter.

The attachment 5 is readilyattached or detached by merely tightening or loosening the screw l0, and the attachment 6 is as-sim- :ply attached or. detached by tightening or loosening the clamp 19. When the screw 10 is tightened the body '7 ofthe attachment 5 is pulled outwardly so that the outer end of the anvil 2 seats firmly against the base of the. recess 9; and before tightening the clamp l9 the outer'end of the member 3 should be brought into contact with the end of that portion of the sleeve 18 which has been bored out to receive it. Thus it is simplo to always replace the attachments so that the readings obtained are always the same when measuring pieces of work of the same size. Moreover the readings may be quickly and accurately checked by advancing the member 3 until the balls 15 and 23 come into contact with one another. In practice We prefer to so proportion the attachments that the readings obtained on say two to three inch micrometers will be correct as to the decimals for work between one and two'incheswhen the attachments are being employed.

While in the foregoing the preferred embodiment of the invention has been described and shown, it is understood that the construction is susceptible to such alterations and modifications as fallwithin the scope of the appended claim.

What we claim is A micrometer attachment comprising a body having; an aperture formed therethrough to receive one extremity of an out side micrometer said body also having a recess formed therein at one end of said aperture to receive the anvil which projects from said micrometer extremity, a screw in threaded engagement with said body and which extends through the latter into the endof said aperture remote from said recess so that when the screw is tightened against the outer side of the micrometer extreinity the base of the recess is drawn against the contact end of said anvil, the end of the body remote from the screw having a cavity formed therein, a block seated on the base of said cavity and having a concavity formed in its outer face, said block being spaced from said anvil by a portion of said body through which a small opening extends connecting the base of the block cavity with the bottom of the recess and forming a knock-out hole, a ball resting against the concavity formed on the block face, and an annular collar having its rear portion internally threaded and an opening .formed centrally through its front face through which-the ball projects, the outer extremity of the body being externally threaded to receive said collar.

WALTER HEeKERsnoRF. HENRY POPPENHAEGER. 

